Complex electronic devices such as, for example, printed circuits, integrated circuits and the like, are typically produced through photo etching or screen printing techniques. As one example, a printed circuit board comprised of an insulating substrate having a conductive sheet adhered to one of its major surfaces, is coated with photo-resist material. A mask is placed over the conductive sheet containing the photo-resist coating, and the mask and printed circuit board are exposed to light for a suitable time interval. The printed circuit board is then placed in a bath containing a suitable etchant. The regions of the photo-resist which have been exposed to light are immune to the etchant, whereas the remaining regions typically containing a conductive film, which have not been exposed to light are removed by the etchant, thereby forming a pattern which may be described as printed wiring, upon the insulating substrate. The remaining photo-resist material may then be removed by a suitable etchant.
Resistances or other active or passive electrical elements may be formed directly upon the printed circuit board or other electronic device through a technique employing screens provided with a pattern conforming to the desired resistance elements, said screen being positioned upon the printed wiring surface of the printed circuit board. A resistive ink is placed upon the screen and is transferred to the printed circuit board by operation of a squeegee which is moved across the surface of said screen to force the resistive solution through the screen in accordance with the aforementioned pattern provided therein. The reduced size and intricacy of the printed wiring pattern and the resistance elements printed thereon necessitates that the various patterns provided thereon be in absolute registration, which is conventionally achieved by providing registration patterns respectively on the screen and mask, on the one hand, and the printed circuit board on the other hand. The registration pattern which must be provided to assure precise registration must be printed or otherwise machined into the printed circuit board, necessitating the provision of additional steps in its fabrication and further reducing the area remaining for receipt of the printed wiring and resistor patterns. In addition, each time a printed wiring board is removed, another registration operation must be performed when a new printed wiring board is placed upon the registration apparatus, thereby reducing overall productivity.